PORT-AU-PRINCE, HAITI, JAN. 7 (MONDAY) -- A key member of the ousted Duvalier regime seized the National Palace after heavy gunfire late Sunday and declared himself provisional president.

The situation remained confused early today, and it was not immediately known if there was any bloodshed.

The apparent military coup came exactly a month before Jean-Bertrand Aristide, a leftist Roman Catholic priest elected Dec. 16 in the country's first free and peaceful nationwide vote, was to be sworn in as president.

Aristide's whereabouts were not immediately known.

Roger Lafontant, the reputed head of the dreaded Tonton Macoute militia that enforced the Duvalier regime, announced the takeover on national radio early today.

He spoke one minute after caretaker President Ertha Pascal-Trouillot announced her resignation over the radio.

The Caribbean nation has had five governments in the tumultous half decade since Jean-Claude "Baby Doc" Duvalier fled into exile in France on Feb. 7, 1986.

Pascal-Trouillot's announcement came at 12:40 a.m. EST, 2 1/2 hours after heavy gunfire broke out at the National Palace.

Less than an hour before the announcement, a source close to Aristide said the president-elect was safe but gave no details.

Aristide, who has survived several assassination attempts, is a self-proclaimed champion of Haiti's impoverished majority. The 37-year-old priest won two-thirds of the vote in last month's election.

His ascendance was opposed by such Duvalierists as Lafontant, who returned last August from five years of exile in the Dominican Republic. He was barred from the presidential race on a technicality and threatened to prevent Aristide from taking office. In several interviews he had said, however, that he would fight Aristide nonviolently.

Speaking from the palace, Pascal-Trouillot said:

"The armed forces have done their utmost to protect life and property and maintain law and order," but "government has become impossible to run. For the happiness of this land that all of us love dearly, I am forced to resign as provisional president."

One minute later, Lafontant came on the air and said: "On request of the armed forces and police, I assume the provisional presidency of the republic this morning."

The impoverished nation of 6 million people has been ruled almost exclusively by tyrants since gaining indepedence from France in 1804.

Aristide was to be inaugurated Feb. 7, the fifth anniversary of Jean-Claude Duvalier's fall.

Lafontant served as interior and defense minister from July 1982 to September 1985. He lost his position in a power shuffle in late 1985 shortly before Duvalier was forced into exile by a popular uprising.

A gynecologist, Lafontant first rose to prominence as a medical student when he helped Duvalier's father, Francois "Papa Doc," crush a student-led strike. He formed a student unit of the Tonton Macoutes and continued to be associated with the infamous militia throughout his career.

In the 1970s, Jean-Claude Duvalier appointed Lafontant consul general in Montreal and then in New York.

A recent report by the National Coalition for Haitian Refugees and Americas Watch quoted former exiles as saying he used those positions to spy on opposition activists.

He is believed to have headed the Tonton Macoutes from 1979 to 1980 and was later a member of the notorious political police force known as the Detective Service. He also served as a special security adviser to Jean-Claude Duvalier.